ALCOHOLISM ABOLISHES THE GAMMA-AMINOBUTYRIC-ACID (GABA)ERGIC CONTROL OF GH SECRETION IN HUMANS

In order to establish possible alterations in the gamma-aminobutyric a cid (GABA)ergic control of growth hormone (GH) secretion in alcoholics , 800 mg sodium valproate (a drug enhancing endogenous GABA activity), 10 mg baclofen (a GABAB receptor agonist) or a placebo were given ora lly to nine normal men (age 38-48 years) and nine 2-4-week-abstinent a lcoholics (age 35-50 years; duration of alcohol consumption 3-6 years) . Blood samples for GH assay were taken every 30 min for the next 150 min. Both drugs induced a significant increment in serum GH levels in the normal controls; mean peak was 7.2 and 3.27 times higher than base line after sodium valproate and baclofen, respectively. In contrast, G H secretion in alcoholic patients did not change after baclofen or sod ium valproate administration. Placebo administration did not modify GH secretion in any subject. In concurrence with previous reports showin g alterations of GABAergic neurotransmission in the central nervous sy stem of patients affected by alcoholism, these data show the loss of t he GABAergic mechanism(s) underlying the GH response to sodium valproa te and/or baclofen action in alcoholism. (C) 1998 Elsevier Science, In c.